Save big at tax time by improving your home’s efficiency with these energy-smart upgrades. Purchase and install any combination of qualifying products by December 31, 2010, and you’ll earn up to $1,500 in one-time tax credits as you expand in-home comfort, reduce air pollution and lock in energy savings. All items net the equivalent of 30 percent of their cost in credits, and some allow you to earn even more than the $1,500 standard cap!